Voltage regulators having a topology carrying out solid-state switching of unregulated voltage (typically across an inductor) for short intervals of time have gained wide acceptance in the electronics arts. Somewhat recently manifested as small, modular a d.c.-to-d.c. converters, the devices may be group packaged in a variety of configurations to provide a.c.-to-d.c. power supplies typically seen employed in computer, test and telecommunication systems. While the modular converters hold continuing promise for highly efficient performance, they necessarily are configured having a heat sinking function as part of their containment structures. Typically, the switching circuit components are fabricated in close, heat transferring adjacency with flat metal heat transfer surfaces.
By combining a number of the converter modules, the system designer readily achieves a variety of desired low voltage outputs and a select parallel interconnecting of the discrete modules provides for outputs of varying current capacity.
In general, practical combinations of the converter modules requires a packaging configuration for them which includes front end a.c. input treatment and a packaging geometry where they are mutually associated in relatively close adjacency. Such close spacing heretofore has engendered heat build-up difficulties and consequent degrading of the power supply packages. Typically, the converter modules employed are each prepackaged as "bricks" of thin rectangular shape. Each such module package then is coupled within an overall housing in combination with front-end circuitry and the like and fans are utilized for the purpose of removing converter-generated heat from the overall package. Because the typical converter module is fashioned having output and input terminals at what may be considered the "narrow" end thereof, a practical coupling of the power supply package within a given electronics system calls for substantial cabling from the power supply package at the end of the discrete modules and into buses leading to back planes and the like. This cabling has been found to hinder cooling air flow in the power supply packages with the consequence of highly undesirable heat build-up. Conventional packaging also positions the front end treatment circuitry within fan developed air flow upstream from the modules, thus detracting from the heat removing capacity of the air flow.